There’s an eerie sound coming from the Caribbean Sea, and for most of human history, no one even knew of it.
It’s too low for humans to hear with the naked ear, so low and subtle that it was first discovered by a team of scientists studying ocean pressure models. When looking at the Caribbean Sea, something didn’t add up.
The scientists, led by Chris Hughes of the University of Liverpool, noticed that in and around the basin that contains the Caribbean Sea, their models were showing unexplainable pressure oscillations in the water on a massive scale.
Maddie Stone, with Gizmodo, has more:
After spotting the weird oscillations in models, Hughes and his colleagues decided to see if they could observe the phenomenon in the ocean. Sure enough, they did. Combining pressure readings collected from the bottom of the Caribbean Sea between 1958 and 2013 with tide gauge records and data from NASA’s Grace satellite, the researchers discovered that the basin of Caribbean Sea acts like a giant whistle.
“You have a current that flows east to west through the Caribbean Sea,” Hughes explained. “It’s very narrow and quite strong. Just like a narrow jet of air, it becomes unstable and creates eddies.”
When these currents hit the western edge of the basin, they die out only to appear again on the eastern edge, a phenomenon that has been called the “Rossy wormhole.” (Wormholes are hypothetical features of spacetime that directly link seemingly distant regions of space. Stuff that falls into a wormhole would seem to disappear only to mysteriously reappear elsewhere.)
What scientists recently discovered is that these waves will resonate as they strike the western edge. The impact of those waves, coupled with the way they bounce off the coasts of Nicaragua, Costa Rica, and Panama, creates a “sound” in the gravitational field of the Earth. A gravity whistle, if you will.
This low-pitched hum has been dubbed the “Rossby Whistle” in a paper soon to be published in Geophysical Research Letters.
In the case of the Caribbean, the sheer size of the “whistle” means the frequency of these waves is extremely low. The waves take 120 days to cross the basin, and the resulting frequency is an A-flat, though it’s a very low A-flat,some 30 octaves lower than the lowest sound a piano can make.
The Rossby Whistle may be more than just a curiosity, too. The team will continue monitoring the basin to see if it reveals the times of the year when coastal flooding is more likely.
Photo credit: Luis Barreto / Wikimedia Commons / (CC BY-NC-ND 2.0)